Abstract

Background

Color additives requiring batch certification by the U.S. Food and Drug Administration have Code of Federal Regulations (CFR) specification limits for certain elements and are usually analyzed by x-ray fluorescence spectrometry (XRF). However, analysis of some color additives presents difficulties.

Objective

An XRF method was developed for quickly determining whether barium sulfate-containing color additives certifiable as D&C Red No. 6 lakes and D&C Red No. 7 lakes meet the CFR specifications for arsenic (As) and lead (Pb).

Method

Difficulties in preparing XRF standards and analyzing As and Pb in matrices with the heavy x-ray absorber barium (Ba) were overcome by first preparing As- and Pb-fortified cellulose, then blending color additive samples with fortified and unfortified cellulose to produce XRF calibration materials. Satisfactory compensation for changes in intensity caused by Ba absorption was achieved by measuring varying concentrations of As and Pb at several concentrations of Ba.

Results

Test samples of barium sulfate-containing D&C Red No. 6 lakes and D&C Red No. 7 lakes were analyzed by the XRF method and by an inductively coupled plasma-mass spectrometry (ICP-MS) method.

Conclusions

The ICP-MS method poses some difficulties and is time consuming. In contrast, the XRF method requires very little sample preparation, is nondestructive, uses calibrations that are stable for long periods of time, and offers acceptable determination limits (1 mg/kg As, 4 mg/kg Pb) which are less than the CFR specification limits (3 mg/kg As, 20 mg/kg Pb).

Highlights

The new XRF method is applicable for use in routine batch certification.

中文翻译：

---

X射线荧光光谱法测定D＆C红色6号色淀和D＆C红色7号色淀中含有硫酸钡的砷和铅

抽象的

背景

需要美国食品和药物管理局批量认证的色料对某些元素有联邦法规（CFR）规范限制，通常通过X射线荧光光谱（XRF）进行分析。然而，对某些颜色添加剂的分析存在困难。

客观的

开发了一种XRF方法，用于快速确定可认证为D＆C红色6号色淀和D＆C红色7号色淀的含硫酸钡的色料是否满足砷（As）和铅（Pb）的CFR规范。

方法

通过首先制备经As和Pb强化的纤维素，然后将颜色添加剂样品与经过强化和未经强化的纤维素混合以进行XRF校准，克服了制备XRF标准品以及使用重X射线吸收剂钡（Ba）分析基质中As和Pb的难题。材料。通过测量几种浓度的钡中不同浓度的砷和铅，可以令人满意地补偿由钡吸收引起的强度变化。

结果

通过XRF方法和电感耦合等离子体质谱法（ICP-MS）分析了含硫酸钡的D＆C红色6号色淀和D＆C红色7号色淀的样品。

结论

ICP-MS方法带来一些困难并且费时。相比之下，XRF方法只需要很少的样品制备，无损检测，可使用长时间稳定的校准，并提供可接受的测定限（1 mg / kg砷，4 mg / kg铅），低于CFR规格限制（3 mg / kg砷，20 mg / kg铅）。

强调

新的XRF方法适用于常规批量认证。